P2E7F code meaning
A/C Compressor Control Module Internal Temperature Sensor B Circuit Low
Powertrain system Generic code P2Exx codes Check engine light
What P2E7F means
P2E7F is the low-signal counterpart: sensor B inside the compressor control module reports a value below its valid band, which for a sensor with falling output means an impossibly hot reading. GM's comparable code on the compressor IGBT sensor is P0D78: the 2011 Volt fails above 274 °C, the 2018 and 2019 tables above 150 °C, with the compressor detecting the condition itself and passing it on over GMLAN, Type B. No manufacturer documents P2E7F. A short on the sensor path is the usual explanation. Genuine overheating of the power stage, for instance from too little refrigerant flow, should still be ruled out, because controllers like the one in a Mitsubishi Heavy Industries patent slow or stop the compressor when it runs too hot. The cold side is P2E7E.
P2E7F at a glance
- Check engine lightYes, usually on
- Emissions testNot an emissions code
- Limp modeNot expected
- Repair difficultyWorkshop only
- Typical labor1 to 5 hours
- Clears after repairAfter a drive cycle
Symptoms of P2E7F
- Compressor derates or shuts down for overheat protection
- Air conditioning blows warm, battery cooling may be limited
- MIL possible after two drive cycles depending on manufacturer
Common causes of P2E7F
- Most likelyShort circuit in the sensor B path on the control board
- PossibleMeasuring circuit of the compressor controller defective
- Less likelyPower stage genuinely overheating, e.g. low refrigerant charge
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Ac compressor cm internal temp sensor bAc compressor module
What each part of P2E7F means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| 7F | The exact fault in that area. |
What to do next
- Note P2E7F and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P2E7F
What does P2E7F mean?
P2E7F means "A/C Compressor Control Module Internal Temperature Sensor B Circuit Low". P2E7F is the low-signal counterpart: sensor B inside the compressor control module reports a value below its valid band, which for a sensor with falling output means an impossibly hot reading. It is a generic code, so it means the same on every make.
Is it safe to drive with P2E7F?
Usually yes, for a short time, if the check engine light is steady and the car drives normally. If the light flashes or the car runs badly, stop and have it checked.
Will P2E7F fail an emissions test?
P2E7F is not an emissions code, so on its own it usually does not fail an emissions test. Other stored codes or a lit check engine light still can.
How hard is P2E7F to fix?
Difficulty: workshop only. A typical repair takes 1 to 5 hours of work. This is a job for a workshop.
Will P2E7F clear itself after the repair?
After the repair the car has to complete a drive cycle (a mix of city and highway driving) before the test runs again. Until then the readiness monitor shows "not ready", which can fail an inspection.